| Server IP : 88.99.149.37 / Your IP : 216.73.216.141 Web Server : nginx/1.31.2 System : Linux server-88-99-149-37 6.12.0-124.56.5.el10_1.x86_64 #1 SMP PREEMPT_DYNAMIC Fri May 15 06:12:08 EDT 2026 x86_64 User : muralimurth ( 1015) PHP Version : 8.4.23 Disable Function : exec,system,passthru,shell_exec,proc_close,proc_open,dl,popen,show_source,posix_kill,posix_mkfifo,posix_getpwuid,posix_setpgid,posix_setsid,posix_setuid,posix_setgid,posix_seteuid,posix_setegid,posix_uname MySQL : OFF | cURL : ON | WGET : ON | Perl : ON | Python : OFF | Sudo : ON | Pkexec : ON Directory : /usr/local/mysql/mysql-test/main/ |
Upload File : |
set @save_optimizer_switch=@@optimizer_switch;
create table t1 (a int);
create table t2 (b int);
insert into t1 values (null), (1), (2), (3);
insert into t2 values (3), (4);
set @@optimizer_switch = "materialization=on,in_to_exists=off,semijoin=off";
explain format=json select * from t1 where a in (select b from t2);
EXPLAIN
{
"query_block": {
"select_id": 1,
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows": 4,
"filtered": 100,
"attached_condition": "<in_optimizer>(t1.a,t1.a in (subquery#2))"
}
}
],
"subqueries": [
{
"materialization": {
"query_block": {
"select_id": 2,
"nested_loop": [
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 2,
"filtered": 100
}
}
]
}
}
}
]
}
}
# "Complete match" execution strategy
analyze format=json select * from t1 where a in (select b from t2);
ANALYZE
{
"query_optimization": {
"r_total_time_ms": "REPLACED"
},
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 25,
"attached_condition": "<in_optimizer>(t1.a,t1.a in (subquery#2))"
}
}
],
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup",
"r_loops": 3,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
]
}
}
}
]
}
}
# "Partial match" is used due to NOT IN
analyze format=json select * from t1 where a not in (select b from t2);
ANALYZE
{
"query_optimization": {
"r_total_time_ms": "REPLACED"
},
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 50,
"attached_condition": "!<in_optimizer>(t1.a,t1.a in (subquery#2))"
}
}
],
"subqueries": [
{
"materialization": {
"r_strategy": "null-aware index_lookup",
"r_loops": 4,
"r_index_lookups": 3,
"r_partial_matches": 1,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
]
}
}
}
]
}
}
# Subselect in GROUP BY
analyze format=json select a from t1 group by a in (select b from t2);
ANALYZE
{
"query_optimization": {
"r_total_time_ms": "REPLACED"
},
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"filesort": {
"sort_key": "<in_optimizer>(t1.a,t1.a in (subquery#2))",
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"r_used_priority_queue": false,
"r_output_rows": 3,
"r_buffer_size": "REPLACED",
"r_sort_mode": "sort_key,rowid",
"temporary_table": {
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
],
"subqueries": [
{
"materialization": {
"r_strategy": "null-aware index_lookup",
"r_loops": 4,
"r_index_lookups": 3,
"r_partial_matches": 1,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
]
}
}
}
]
}
}
}
}
analyze format=json select a from t1 group by a not in (select b from t2);
ANALYZE
{
"query_optimization": {
"r_total_time_ms": "REPLACED"
},
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"filesort": {
"sort_key": "!<in_optimizer>(t1.a,t1.a in (subquery#2))",
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"r_used_priority_queue": false,
"r_output_rows": 3,
"r_buffer_size": "REPLACED",
"r_sort_mode": "sort_key,rowid",
"temporary_table": {
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
],
"subqueries": [
{
"materialization": {
"r_strategy": "null-aware index_lookup",
"r_loops": 4,
"r_index_lookups": 3,
"r_partial_matches": 1,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
]
}
}
}
]
}
}
}
}
# Subselect in ORDER BY
analyze format=json select a from t1 order by a in (select b from t2);
ANALYZE
{
"query_optimization": {
"r_total_time_ms": "REPLACED"
},
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"read_sorted_file": {
"r_rows": 4,
"filesort": {
"sort_key": "<in_optimizer>(t1.a,t1.a in (subquery#2))",
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"r_used_priority_queue": false,
"r_output_rows": 4,
"r_buffer_size": "REPLACED",
"r_sort_mode": "sort_key,addon_fields",
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
}
}
],
"subqueries": [
{
"materialization": {
"r_strategy": "null-aware index_lookup",
"r_loops": 4,
"r_index_lookups": 3,
"r_partial_matches": 1,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
]
}
}
}
]
}
}
# Subselect in HAVING
analyze format=json select a from t1 having a not in (select b from t2);
ANALYZE
{
"query_optimization": {
"r_total_time_ms": "REPLACED"
},
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"having_condition": "!<in_optimizer>(t1.a,t1.a in (subquery#2))",
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
],
"subqueries": [
{
"materialization": {
"r_strategy": "null-aware index_lookup",
"r_loops": 4,
"r_index_lookups": 3,
"r_partial_matches": 1,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
]
}
}
}
]
}
}
# Nested IN
analyze format=json select a from t1 where a in (select a from t1 where a in (select b from t2));
ANALYZE
{
"query_optimization": {
"r_total_time_ms": "REPLACED"
},
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 25,
"attached_condition": "<in_optimizer>(t1.a,t1.a in (subquery#2))"
}
}
],
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup",
"r_loops": 3,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 25,
"attached_condition": "<in_optimizer>(t1.a,t1.a in (subquery#3))"
}
}
],
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup",
"r_loops": 3,
"query_block": {
"select_id": 3,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
]
}
}
}
]
}
}
}
]
}
}
create table t3 (c int);
insert into t3 (c) values (3), (null), (4);
# Subquery in ON-clause of outer join
analyze format=json select a from t1 left join t2 on a not in (select c from t3);
ANALYZE
{
"query_optimization": {
"r_total_time_ms": "REPLACED"
},
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"const_condition": "1",
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
},
{
"block-nl-join": {
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
},
"buffer_type": "flat",
"buffer_size": "87",
"join_type": "BNL",
"attached_condition": "trigcond(trigcond(!<in_optimizer>(t1.a,t1.a in (subquery#2))))",
"r_loops": 4,
"r_filtered": 50,
"r_unpack_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_effective_rows": 2
}
}
],
"subqueries": [
{
"materialization": {
"r_strategy": "null-aware index_lookup",
"r_loops": 4,
"r_index_lookups": 3,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t3",
"access_type": "ALL",
"r_loops": 1,
"rows": 3,
"r_rows": 3,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
]
}
}
}
]
}
}
analyze format=json
select (b, b + 1, b + 2) not in
(select count(distinct a), a + 1, a + 2 from t1 group by a + 1, a + 2)
from t2;
ANALYZE
{
"query_optimization": {
"r_total_time_ms": "REPLACED"
},
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 2,
"r_rows": 2,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
],
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;full scan for partial match",
"r_loops": 2,
"r_index_lookups": 2,
"r_partial_matches": 2,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"read_sorted_file": {
"r_rows": 4,
"filesort": {
"sort_key": "t1.a + 1, t1.a + 2",
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"r_used_priority_queue": false,
"r_output_rows": 4,
"r_buffer_size": "REPLACED",
"r_sort_mode": "sort_key,addon_fields",
"table": {
"table_name": "t1",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
}
}
]
}
}
}
]
}
}
drop table t1, t2, t3;
#
# Tables with more than one column
#
create table t1 (a1 char(1), a2 char(1));
insert into t1 values (null, 'b');
create table t2 (b1 char(1), b2 char(2));
insert into t2 values ('a','b'), ('c', 'd'), (null, 'e'), ('f', 'g');
# Force rowid-merge partial matching
set @@optimizer_switch="partial_match_rowid_merge=on,partial_match_table_scan=off";
explain format=json select * from t1 where (a1, a2) not in (select b1, b2 from t2);
EXPLAIN
{
"query_block": {
"select_id": 1,
"const_condition": "!<in_optimizer>((NULL,'b'),(NULL,'b') in (subquery#2))",
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "system",
"rows": 1,
"filtered": 100
}
}
],
"subqueries": [
{
"materialization": {
"query_block": {
"select_id": 2,
"nested_loop": [
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 4,
"filtered": 100
}
}
]
}
}
}
]
}
}
analyze format=json select * from t1 where (a1, a2) not in (select b1, b2 from t2);
ANALYZE
{
"query_optimization": {
"r_total_time_ms": "REPLACED"
},
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"const_condition": "!<in_optimizer>((NULL,'b'),(NULL,'b') in (subquery#2))",
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "system",
"r_loops": 0,
"rows": 1,
"r_rows": null,
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": null
}
}
],
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;array merge for partial match",
"r_loops": 1,
"r_partial_matches": 1,
"r_partial_match_buffer_size": "REPLACED",
"r_partial_match_array_sizes": ["4", "3"],
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
]
}
}
}
]
}
}
# Force table scan partial matching
set @@optimizer_switch="partial_match_rowid_merge=off,partial_match_table_scan=on";
analyze format=json select * from t1 where (a1, a2) not in (select b1, b2 from t2);
ANALYZE
{
"query_optimization": {
"r_total_time_ms": "REPLACED"
},
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"const_condition": "!<in_optimizer>((NULL,'b'),(NULL,'b') in (subquery#2))",
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "system",
"r_loops": 0,
"rows": 1,
"r_rows": null,
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": null
}
}
],
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;full scan for partial match",
"r_loops": 1,
"r_partial_matches": 1,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
]
}
}
}
]
}
}
# Subquery in SELECT list
explain format=json select t1.*, (a1, a2) in (select * from t2) as in_res from t1;
EXPLAIN
{
"query_block": {
"select_id": 1,
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "system",
"rows": 1,
"filtered": 100
}
}
],
"subqueries": [
{
"materialization": {
"query_block": {
"select_id": 2,
"nested_loop": [
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"rows": 4,
"filtered": 100
}
}
]
}
}
}
]
}
}
analyze format=json select t1.*, (a1, a2) in (select * from t2) as in_res from t1;
ANALYZE
{
"query_optimization": {
"r_total_time_ms": "REPLACED"
},
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "system",
"r_loops": 0,
"rows": 1,
"r_rows": null,
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": null
}
}
],
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;full scan for partial match",
"r_loops": 1,
"r_partial_matches": 1,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
]
}
}
}
]
}
}
analyze format=json select t1.*, (a1, a2) not in (select * from t2) as in_res from t1;
ANALYZE
{
"query_optimization": {
"r_total_time_ms": "REPLACED"
},
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "system",
"r_loops": 0,
"rows": 1,
"r_rows": null,
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": null
}
}
],
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;full scan for partial match",
"r_loops": 1,
"r_partial_matches": 1,
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
]
}
}
}
]
}
}
set @@optimizer_switch="partial_match_rowid_merge=on,partial_match_table_scan=off";
analyze format=json select t1.*, (a1, a2) in (select * from t2) as in_res from t1;
ANALYZE
{
"query_optimization": {
"r_total_time_ms": "REPLACED"
},
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "system",
"r_loops": 0,
"rows": 1,
"r_rows": null,
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": null
}
}
],
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;array merge for partial match",
"r_loops": 1,
"r_partial_matches": 1,
"r_partial_match_buffer_size": "REPLACED",
"r_partial_match_array_sizes": ["4", "3"],
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
]
}
}
}
]
}
}
analyze format=json select t1.*, (a1, a2) not in (select * from t2) as in_res from t1;
ANALYZE
{
"query_optimization": {
"r_total_time_ms": "REPLACED"
},
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t1",
"access_type": "system",
"r_loops": 0,
"rows": 1,
"r_rows": null,
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": null
}
}
],
"subqueries": [
{
"materialization": {
"r_strategy": "index_lookup;array merge for partial match",
"r_loops": 1,
"r_partial_matches": 1,
"r_partial_match_buffer_size": "REPLACED",
"r_partial_match_array_sizes": ["4", "3"],
"query_block": {
"select_id": 2,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"nested_loop": [
{
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 4,
"r_rows": 4,
"r_table_time_ms": "REPLACED",
"r_other_time_ms": "REPLACED",
"r_engine_stats": REPLACED,
"filtered": 100,
"r_filtered": 100
}
}
]
}
}
}
]
}
}
drop table t1,t2;
set @@optimizer_switch=@save_optimizer_switch;